1. Field of the Invention
The present invention relates to a slider assembly, and more particularly, to a slider assembly for use in a cellular phone.
2. Discussion of Related Technology
As shown in FIG. 25, a sliding-type cellular phone comprises a main body 1 on which a plurality of keys 3 are installed and a cover 2 installed slidably over a surface of the main body 1 on which the keys 3 are installed. A liquid crystal display 4 is installed on a front surface of the cover 2. In the sliding-type cellular phone as described above, a slider assembly 100 shown in FIG. 25 or 26 is installed between the main body 1 and the cover 2 to allow the cover 2 to be slid with respect to the main body 1.
The slider assembly shown in FIG. 25 comprises a fixing plate 110 fixed to the main body 1; a sliding plate 170 fixed to a surface of the cover facing the main body; and an up/down positioning means 140 which includes one end hinged to the fixing plate 110 and the other end hinged to the sliding plate 120 to impart an elastic force to the cover 2 in a direction in which the cover is closed or opened with respect to a certain sliding point. The up/down positioning means includes a cylinder 141 in which a compression spring is received and a rod 142 which is installed to be movably received in the cylinder 141 while pushing the compression spring. As shown in the figure, an end of the cylinder 141 is hinged to the fixing plate 110, and an opposite end of the rod 142 is hinged to the sliding plate 120.
Another type of exemplary slider assembly 100 is illustrated in FIG. 26. The slider assembly 100 shown in FIG. 26 includes a fixing plate 110 fixed to the main body 1; a sliding plate 120 fixed to a surface of the cover facing the main body; and a pair of torsion springs 130 each having an end hinged to the fixing plate 110 and the other end hinged to the sliding plate. In the slider assembly shown in FIG. 26, the pair of torsion springs 130 are equivalent to the up/down positioning means.
The exemplary slider assembly as described above does not include a function of restricting a sliding length of the sliding plate 120. Accordingly, in order to adjust the upward/downward sliding stroke of the sliding plate 120, a stopper (not shown) for restricting the movement of the sliding plate is installed at the main body or cover of the cellular phone. Further, as shown in FIG. 25, separate dampers 150 for absorbing the shock may be installed at both ends of the sliding plate that collides against the stopper when the cover of the cellular phone is slid. Therefore, a process for manufacturing the cellular phone is complicated, and thus, the production costs are increased. Meanwhile, the slider assembly of FIG. 25 is superior to the slider assembly of FIG. 26 using the torsion springs in view of their durability, but the former is more complicated and expensive than the latter because the spring and rod 142 is received and assembled in the cylinder 141 and the ends of the cylinder and rod is hingedly coupled to the fixing plate and the sliding plate, respectively.
The slider assembly of in FIG. 26 employs the torsion spring 130 as the up/down positioning means, and thus, the slide assembly can be manufactured through a simple process and at a low cost. However, since it is difficult to manufacture the torsion spring with constant elasticity, every cellular phone cannot have a constant urging force required for sliding the cover. Accordingly, there is a problem that the cellular phones with the uniform urging force required for sliding the cover cannot be manufactured. Further, if the torsion spring 130 is repeatedly used for a long time, excessive deformation is generated at a portion that connects linear and curved portions of the torsion spring 130, and thus, the connecting portion is broken due to fatigue. Consequently, there is another problem in that a durability of the torsion spring is not good.
The discussion in this section is to provide general background information, and does not constitute an admission of prior art.